Robot, an automatic or programmable machine, originally one resembling a human being, derives from Czech robota, forced labour.

One sense, directly derived from the concept of a robot, is that of an autonomous device, usually mobile, with a degree of awareness derived from computer technology; many examples are found in scientific or science fiction contexts, but few have become widely known. Examples include nanobot (Greek nanos, dwarf), a hypothetical robot of molecular dimensions; cryobot (Greek kruos, frost), a NASA-invented device for penetrating deep ice layers to examine what lies beneath; killerbot, an autonomous military killing machine; biobot, a robot which mimics biological behaviour.

The more common sense is of a semi-autonomous software program, usually linked to networking and especially to the Internet and the World Wide Webb. Well-known examples include cancelbot, a program that searches for and deletes specified mailings from Internet newsgroups; knowbot, a program which has reasoning and decision-making capabilities; and spambot, a program which scans Web pages in order to harvest e-mail addresses to which unsolicited commercial advertising (spam) can be sent.

Bot also exists as a word in its own right, in reference to a device of either kind.